Perhaps the two main contemporary formulations of ethical naturalism – Synthetic Ethical Naturalism (SEN) and Analytical Descriptivism – seem to conflict with plausible views about cases where moral debate and disagreement is possible. Both lack safeguards to avoid divergence of reference across different communities, which can scupper the prospects for genuine moral disagreement. I explore the prospects for supplementing both views with Lewis's notion of eligibility, arguing that this can solve the problem for a modified form of analytical descriptivism, and for a modified form of SEN too (though perhaps more controversially). I close by considering the appropriateness of using the notions of eligibility and joint-carving in ethics